Obesity represents the most prevalent of body weight disorders, and it is the most important nutritional disorder in the Western world, with estimates of its prevalence ranging from 30% to 50% of the middle-aged population. The number of overweight and obese Americans has continued to increase since 1960, a trend that is not slowing down. Today, 64.5 percent of adult Americans (about 127 million) are categorized as being overweight or obese. Obesity is becoming a growing concern as the number of people with obesity continues to increase and more is learned about the negative health effects of obesity. Each year, obesity causes at least 300,000 deaths in the U.S., and healthcare costs of American adults with obesity amount to more than $125 billion (American Obesity Association). Severe obesity, in which a person is 100 pounds or more over ideal body weight, in particular poses significant risks for severe health problems. Accordingly, a great deal of attention is being focused on treating patients with obesity.
Even mild obesity increases the risk for premature death, diabetes, hypertension, atherosclerosis, gallbladder disease and certain types of cancer. Because of its high prevalence and significant health consequences, its treatment should be a high public health priority. Therefore, a better understanding of the mechanism for weight loss is needed. Moreover, a need exists for better methods and therapeutics for treating obesity and inducing weight loss.